DSpace Coleção:http://repositorio.ufla.br/jspui/handle/1/28
Sun, 07 Jun 2020 10:32:16 GMT2020-06-07T10:32:16ZFisiologia metabólica e sinalização no desenvolvimento reprodutivo da cana-de-açúcar sob a influência de piraclostrobinahttp://repositorio.ufla.br/jspui/handle/1/39595
Título: Fisiologia metabólica e sinalização no desenvolvimento reprodutivo da cana-de-açúcar sob a influência de piraclostrobina
Autor: Linhares Neto, Manoel Viana
Resumo: Sugarcane (Saccharum spp.) is one of the most important crops, being a source of worldwide industrial production in both the food and bioenergy sectors. Flowering directly affects its production, since this process consumes sucrose stored in the stem for the development of floral structures. One of the strategies in the creation of new technologies for production gains is the use of the fungicide pyraclostrobin, which has often been related to physiological effects on plants. Data still under analysis, support the hypothesis that pyraclostrobin can promote some type of signaling with the induction of flowering, supposedly, via sugar and nitrogen metabolism. In this sense, the objective of this work was to investigate the influence of pyraclostrobin on photosynthetic and respiratory responses, as well as on the production of nitric oxide (NO), in sugarcane. Additionally, the objective was to evaluate the consequences of these effects on growth, development, and flowering based on RNA-seq analyzes. For that, an experiment was carried out with plants grown in a pot and another experiment under field conditions. In the pot experiment, photosynthetic parameters, respiration, chlorophyll, and carotenoid contents, and nitric oxide production were evaluated. In the field experiment, a new management system was evaluated to optimize and validate the effects on growth and development, and flowering. Also, the data were investigated from the analysis of the plant transcriptome with and without the application of pyraclostrobin. The results showed that sugarcane plants, submitted to treatment with pyraclostrobin, showed faster responses to the increase in light radiation. There were increases both in respiration and in the levels of photosynthetic pigments. NO production was increased in the leaves of treated plants. The analyzed variables had different responses with treatment. In the field, the plants had an increase in the diameter and height of the stalk, showed a reduction in the pith process, an extension of the vegetative growth phase and an increase in the final productivity. Qualitative data from the visualization of the meristematic region showed that the model of 3 applications of pyraclostrobin has the potential to inhibit the flowering of sugar cane. RNA-seq analyzes suggest that pyraclostrobin is involved in stress regulation, in thermal tolerance mechanisms linked to plant production, in photosynthetic regulatory mechanisms, in impacts on source-drain relationships, chloroplast and mitochondrial signaling, and regulation in the flowering induction.Tue, 31 Mar 2020 00:00:00 GMThttp://repositorio.ufla.br/jspui/handle/1/395952020-03-31T00:00:00ZEtileno e o florescimento de Coffea arabica: identificação in silico e análise da expressão gênica da via de biossíntese e sinalização em resposta ao déficit hídrico, reidratação e ação do 1-Metilciclopropenohttp://repositorio.ufla.br/jspui/handle/1/39576
Título: Etileno e o florescimento de Coffea arabica: identificação in silico e análise da expressão gênica da via de biossíntese e sinalização em resposta ao déficit hídrico, reidratação e ação do 1-Metilciclopropeno
Autor: Santos, Iasminy Silva
Resumo: Brazil is the largest producer and exporter of processed coffee in the world and based on the export volume forecast for 2020, those will continue. One of the most important t points is the coffee crop is the quality of beverage for the final consumer, and one of the most important factor influencing on the classification of the quality cup is the fruit ripening stage at the time of harvest. The degree of ripeness of the fruits is related to the flowering events that, in the coffee tree, can occur many times during the same production cycle. This sequential flowering results from the asynchronous development of the flower buds and is an intrinsic characteristic of coffee species, resulting in the uneven maturation of fruits. Drought periods accompanied by rain or irrigation to synchronize the flowering time of coffee tree have been reported, but the influence of these events on the internal processes that are involved in the induction and floral opening of Coffea arabica are not yet fully understood. It is known that during the water deficit changes at the cellular, molecular level occur to coordinate responses in unfavorable conditions. Plant hormones are involved in the quickly response to biotic and abiotic stresses, and ethylene is one of the plant hormones responsive to water deficit. Therefore, the influence of ethylene on coffee flowering was suggested based on the requirements for the floral buds development in coffee. In this sense, the observation of promoted anthesis by an ethylene action inhibitor was unexpected. 1-Methylcyclopropene (1-MCP) is widely marketed as an ethylene action antagonist, but when used in coffee plants showed a positive regulation of genes in the ethylene biosynthesis enzymes (ACS and ACO) and signaling (ETR4) of this hormone in. It was argued that the increase in ethylene biosynthesis may have raised the hormone levels and this would have regulated the opening time of coffee flowers. However, there is not consistent information on the changes in ethylene metabolism triggered by different water conditions and by 1-MCP. Aiming to increase knowledge about the influence of ethylene on the flowering of Coffea arabica, this study analyzed in silico possible genes orthologists from ACS and ACO, and analyzed the gene expression by RT-qPCR of eleven genes related to the biosynthesis and signaling pathways of ethylene in coffee trees submitted to different water treatments and treated with 1-MCP. The leaf water potential was evaluated during the experimental period, in addition to the quantification of ethylene production in each treatment. Coffea arabica has a small multigene family for the enzymes ACS and ACO. The level of expression of these homologous genes is regulated by the water condition and there is a unique and overlapping expression pattern in different organs. 1-MCP positively regulates the biosynthesis pathway by increasing the ethylene concentration in Coffea arabica leaves, possibly through a feedback mechanism due to the loss of negative feedback. However, 1-MCP suppresses the expression of the CaETR1-like receptor, possibly promoting a fine adjustment in sensitivity to ethylene.Tue, 31 Mar 2020 00:00:00 GMThttp://repositorio.ufla.br/jspui/handle/1/395762020-03-31T00:00:00ZAmbiente de cultivo e respostas morfofisiológicas durante o processo de micropropagação de Annona glabra L.http://repositorio.ufla.br/jspui/handle/1/36969
Título: Ambiente de cultivo e respostas morfofisiológicas durante o processo de micropropagação de Annona glabra L.
Autor: Deccetti, Soami Fernanda Caio
Resumo: Não disponível.
Descrição: Esta dissertação/tese está disponível online com base na Resolução CEPE nº 090, de 24 de março de 2015, disponível emhttp://www.biblioteca.ufla.br/wordpress/wp-content/uploads/res090-2015.pdf, que dispõe sobre a disponibilização da coleção retrospectiva de teses e dissertações online no Repositório Institucional da UFLA, sem autorização prévia dos autores. Parágrafo Único. Caberá ao autor ou orientador a solicitação de restrição quanto à divulgação de teses e dissertações com pedidos de patente ou qualquer embargo similar. Art. 5º A obra depositada no RIUFLA que tenha direitos autorais externos à Universidade Federal de Lavras poderá ser removida mediante solicitação por escrito, exclusivamente do autor, encaminhada à Comissão Técnica da Biblioteca Universitária./ Arquivo gerado por meio da digitalização de material impresso. Alguns caracteres podem ter sido reconhecidos erroneamente.Fri, 27 Sep 2019 00:00:00 GMThttp://repositorio.ufla.br/jspui/handle/1/369692019-09-27T00:00:00ZCaracterísticas fisiológicas de clones de seringueira (Hevea spp.) em função da disponibilidade de água no solohttp://repositorio.ufla.br/jspui/handle/1/36382
Título: Características fisiológicas de clones de seringueira (Hevea spp.) em função da disponibilidade de água no solo
Autor: Santos, Jacqueline Oliveira dos
Resumo: The objective of the present study was to verify metabolic changes related to carbon
assimilation, antioxidant systems and osmolyte production in young plants of four rubber tree
clones (GT1, IAC40, PR255 and RRIM600) submitted to progressive soil water deficit 32 days
of water suspension (32 DIS). After this period of water suspension, the soil was rehydrated for
15 days (15 DRS). Evaluations were made at 32 DIS and 15 DRS for gas exchange and
biochemical analyzes. The water potential was evaluated at 0, 16 and 32 days after the
imposition of the water deficit and at 15 days after irrigation. Relative water content (RWC),
water potential (Ψw), gas exchange, chlorophyll fluorescence, carbon metabolism and
antioxidants as well as proline and glycine betaine were evaluated. The decrease of Ψw led to
decreases in A, gs, and E. In relation to the internal carbon (Ci) only PR255 plants did not
distinguish from the control, other clones reduced their internal carbon contents under water
deficit. However, a recovery of these values was observed for all clones after 15 DRS. The A /
Ci and US ratios were affected by water suppression, generally with increased water use
efficiency in clones and A / Ci reduction. The photochemical process was altered under water
deficit. At 32 DIS, a lower accumulation of dry leaf mass was observed for all the clones. An
increase in the content of AST and AR and amino acids was observed for all clones in 32 DIS.
In relation to total proteins, starch IAPC, INC and SUSY, a decrease occurred in all the clones
at 32 DIS and after the restoration of the irrigation, no differences were observed compared to
irrigated plants with the exception of the GT1 clone that did not differ in the activity of the SPS
enzyme. The water deficit stimulated the enzymatic antioxidant system, the enzymes; SOD,
CAT and APX in general had their activities increased with the return of values in 15 DRS in
which the activity of the antioxidant enzymes remained similar to the control. In this study, an
increase was observed in H2O2 contents under water deficit, in which, after restoration of
irrigation, RRIM600, IAC40 and PR255 clones continued with higher levels compared to
control. The levels of lipid peroxidation (MDA), reached higher levels due to the low water
availability. The water deficiency promoted an accumulation in the contents of PRO and GB
and as in the other characteristics, after the rehydration of the substrate these contents were
similar to their respective controls. Clones GT1, IAC40 and RRIM600 showed superiority to
clone PR255 in terms of stability and efficiency in the use of energy and antioxidant activity
and accumulation of organic osmolytes under conditions of low availability of water. It is
suggested that the clones GT1, IAC 40 and RRIM 600 are more tolerant to water stress and
more suitable for non-traditional areas of rubber tree plantations that present summer or
irregular distribution of rainfall.Wed, 21 Aug 2019 00:00:00 GMThttp://repositorio.ufla.br/jspui/handle/1/363822019-08-21T00:00:00Z